ExampleMultisampleBlit.cpp

Example for rendering something using the multisample. This provides anti aliasing for rendering things in a framebuffer

,glfFramebufferObject

Author

Ingo Schiller / Bogomil Bartzcak

Date

12/2009

/*
 This file is part of the BIAS library (Basic ImageAlgorithmS).

 Copyright (C) 2003-2009    (see file CONTACT for details)
 Multimediale Systeme der Informationsverarbeitung
 Institut fuer Informatik
 Christian-Albrechts-Universitaet Kiel


 BIAS is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.

 BIAS is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public License
 along with BIAS; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


/**
   @example ExampleMultisampleBlit.cpp
   @relates PMDWarp,glfFramebufferObject
   @brief Example for rendering something using the multisample. 
   This provides anti aliasing for rendering things in a framebuffer
   @ingroup g_examples
   @ingroup g_openglframework
   @author Ingo Schiller / Bogomil Bartzcak
   @date 12/2009
*/


#include <OpenGLFramework/RenderingContext/glfPBuffer.hh>
#include <OpenGLFramework/SpecializedBatches/PMDWarp.hh>
#include <OpenGLFramework/Base/glfException.hh>
#include <OpenGLFramework/Base/glfFramebufferObject.hh>


#include <Utils/Param.hh>
#include <Utils/IOUtils.hh>
#include <Base/Image/ImageIO.hh>
#include <Base/Image/Image.hh>
#include <Image/Camera.hh>

#include <Gui/biasgl.h> 
#include <GLviewer/Scenes/ScenePointLight.hh>
#include <GLviewer/GLProjectionParametersPerspective.hh>
#ifdef BIAS_HAVE_OPENSCENEGRAPH
#include <GLviewer/Scenes/ScenePlainOpenSceneGraph.hh>
#define HAVE_A_SCENEGRAPH
#endif
#ifdef BIAS_HAVE_OSG
#include <GLviewer/Scenes/SceneOSG.hh>
#define HAVE_A_SCENEGRAPH
#endif

using namespace std;
using namespace BIAS;



int main(int argc, char* argv[]) 
{
  Param params(true);

  string *model = NULL;
  model = params.AddParamString("Model", "", "",'m',GRP_NOSHOW);
  string *projection = params.AddParamString("Projection", "", "",'p',GRP_NOSHOW);
  int *numSamples = params.AddParamInt("samples", "number of samples used for multi sample buffers", 
                16, 0,16,'b',GRP_NOSHOW);

  if(!IOUtils::ParseCommandLineEvalHelp(params, argc, argv) ) 
    return 0;
  
#ifdef HAVE_A_SCENEGRAPH
  bool hasmodel = false;
#endif
  unsigned int width = 1024;
  unsigned int height = 768;


  glfPBuffer pbuffer;  
  try {  

    glfRenderingContextConfig cfg;
    cfg.width         = 5;                  
    cfg.height        = 5;
    cfg.doubleBuffer  = 0;
    cfg.redSize       = 8;
    cfg.greenSize     = 8;
    cfg.blueSize      = 8;
    cfg.alphaSize     = 0;
    cfg.depthSize     = 24;
    cfg.stencilSize   = 0;

    pbuffer.Init(cfg);  
    pbuffer.MakeCurrent();
    glViewport(0,0,width,height);
  
    /** 
     * Build target fbo with textures
     **/
    glfTexture2D colorTexture;
    colorTexture.Create();
    colorTexture.SetMagFilter(GL_NEAREST);
    colorTexture.SetMinFilter(GL_NEAREST);
    colorTexture.SetWrapS(GL_CLAMP);
    colorTexture.SetWrapT(GL_CLAMP);
    colorTexture.Allocate(width, height, GL_RGB);

    glfTexture2D depthTexture;
    depthTexture.Create();
    depthTexture.SetMagFilter(GL_NEAREST);
    depthTexture.SetMinFilter(GL_NEAREST);
    depthTexture.SetWrapS(GL_CLAMP);
    depthTexture.SetWrapT(GL_CLAMP);
    depthTexture.Allocate(width, height, GL_DEPTH_COMPONENT);

    glfFramebufferObject targetFbo;
    targetFbo.Create();
    targetFbo.AttachTexture(colorTexture, GL_COLOR_ATTACHMENT0_EXT);
    targetFbo.AttachTexture(depthTexture, GL_DEPTH_ATTACHMENT_EXT);
    targetFbo.CheckComplete();       
    
    GLF_THROW_ON_OPENGL_ERROR;

    BIAS::GLProjectionParametersPerspective glParams;    
    glParams.SetSimplePerspectiveCam(60.0, width, height);
    glParams.SetZClippingPlanes(10, 7500);
    if(*projection != "") {
        cout<<"Loading projection:"<<*projection<<endl;
        Projection proj; 
        int ret = proj.XMLRead(*projection);
        if(ret != 0) BIASERR("Reading projection failed!");
        glParams.SetIntrinsics(proj.GetParameters());
        glParams.SetExtrinsics(proj.GetC(),proj.GetQ());
        glParams.SetUndistortion(0.0,0.0,0.0,0.0);
    }
    const BIAS::Vector4<float> cc(0.2, 0.4, 0.1, 1);
    glParams.SetClearColor(cc);
#ifdef BIAS_HAVE_OPENSCENEGRAPH
    BIAS::ScenePlainOpenSceneGraph sceneOSG; 
#endif
#ifdef BIAS_HAVE_OSG
    BIAS::SceneOSG sceneOSG;
#endif
    
#ifdef HAVE_A_SCENEGRAPH
  
    if(*model != ""){ 
        sceneOSG.Init();
        cout<<"Loading model:"<<*model<<endl;
        if(sceneOSG.AppendSubTreeFromFile(*model)>=0)
            hasmodel= true;
    }

    BIAS::ScenePointLight          lightScene;
    lightScene.SetLightAsHeadLight(true);
    lightScene.SetDrawLightPosition(false);
    lightScene.SetAmbient(Vector4<double> (0.3, 0.3, 0.3, 1.0));
    lightScene.SetDiffuse(Vector4<double> (1.0, 1.0, 1.0, 1.0));
    lightScene.SetSpecular(Vector4<double> (0.1, 0.1, 0.1, 1.0));
#endif
    glClearColor(0.0, 1.0, 0.0, 0.0);
    glEnable(GL_MULTISAMPLE);
    glEnable(GL_DEPTH_TEST);
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glClearDepth(1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLineWidth(1);
#ifdef HAVE_A_SCENEGRAPH
    if(hasmodel){
        pbuffer.MakeCurrent();
        glParams.SetRenderTarget(&targetFbo);   
        vector<SceneBase*> scenes; scenes.push_back(&lightScene);
        scenes.push_back(&sceneOSG);
        glParams.Draw(scenes);
        cout<<"Drawing target scene!"<<endl;
    }
#endif 
    glDisable(GL_DEPTH_TEST);
    glLineWidth(5);
    glBegin(GL_LINES);
    glColor3f(0.8,0.8,0.0);
    glVertex2f(0.25,0.25);
    glColor3f(0.0,0.0,1.0);
    glVertex2f(-0.25,-0.25);        
    glEnd();
    
    //write out result to show that we have cleared the target to black, and 0.75 depth width a line
    Camera<unsigned char> resultColor;
    Camera<float> resultDepth;

    colorTexture.CopyToImage(resultColor);
    resultColor.Flip();
    IOUtils::SaveCamera("colorBeforeBlit.mip",resultColor);

    depthTexture.CopyToImage(resultDepth);
    resultDepth.Flip();
    IOUtils::SaveCamera("depthBeforeBlit.mip", resultDepth);

    /** 
     * Build source fbo with multisample renderbuffers
     **/
    glfRenderbuffer colorRenderbuffer;
    colorRenderbuffer.Create(GL_RGBA, width, height, *numSamples);//uses multisampling!
    glfRenderbuffer depthRenderbuffer;
    depthRenderbuffer.Create(GL_DEPTH_COMPONENT, width, height, *numSamples);//uses multisampling!

    glfFramebufferObject sourceFbo;
    sourceFbo.Create();
    sourceFbo.AttachRenderbuffer(colorRenderbuffer, GL_COLOR_ATTACHMENT0_EXT);
    sourceFbo.AttachRenderbuffer(depthRenderbuffer, GL_DEPTH_ATTACHMENT_EXT);
    sourceFbo.CheckComplete();   

    glClearColor(1.0, 0.0, 0.0, 0.0);
    glClearDepth(1.0); 
    glEnable(GL_DEPTH_TEST);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);       
    glLineWidth(1);
    
#ifdef HAVE_A_SCENEGRAPH
    if(hasmodel){
        pbuffer.MakeCurrent();
        glParams.SetRenderTarget(&sourceFbo);
        vector<SceneBase*> scenes; scenes.push_back(&lightScene);
        scenes.push_back(&sceneOSG);
        glParams.Draw(scenes);//glParams.Draw(scenes);      
        cout<<"Drawing source scene!"<<endl;
    }
#endif    
    glDisable(GL_DEPTH_TEST);
    //using immediate mode here avoiding overhead through batch etc...    
    glLineWidth(5); 
    glBegin(GL_LINES);
    glColor3f(0.8,0.8,0.0);
    glVertex2f(0.25,0.25);
    glColor3f(0.0,0.0,1.0);
    glVertex2f(-0.25,-0.25);        
    glEnd();

    if(*numSamples == 0) {
      //write out renderbuffer contents if  multisampling is inactive
      colorRenderbuffer.CopyToImage(resultColor);
      IOUtils::SaveCamera("colorRenderbuffer.mip",resultColor);
      
      depthRenderbuffer.CopyToImage(resultDepth);
      IOUtils::SaveCamera("depthRenderbuffer.mip", resultDepth);
    }
    
    
    glfFramebufferObject::BlitColorBuffer(&sourceFbo, &targetFbo, GL_LINEAR);
    glfFramebufferObject::Blit(&sourceFbo, &targetFbo, GL_DEPTH_BUFFER_BIT);

    GLF_THROW_ON_OPENGL_ERROR;
    
    //write out result to show that we have blitted the source, i.e color is now blue and depth 0.25
    colorTexture.CopyToImage(resultColor);
    resultColor.Flip();
    IOUtils::SaveCamera("colorAfterBlit.mip",resultColor);

    depthTexture.CopyToImage(resultDepth);
    resultDepth.Flip();
    IOUtils::SaveCamera("depthAfterBlit.mip", resultDepth);


  } catch (glfException& e) {
    std::cout << "Error: " << e.GetMessageString() << std::endl;
    pbuffer.Destroy();
    return -1;
  }



  pbuffer.Destroy();
}